This research will develop thin insulating coatings for implant devices that are essentially impermeable to water and tissue fluids. Thin insulating coatings will be fabricated by a low-temperature sputtering process. High quality coatings will be formed into a specially engineered multi layer structure designed to enhance interfacial bonding and eliminate pin-holes. The resultant insulating coatings may be used as an outer protective barrier for neural prosthetic implants, such as neural microprobes, and their connecting fixtures.